1. Field of the Invention
The present invention relates to a disk device for driving a disk. More particularly, the present invention relates to a disk device for driving a disk, the disk device having a mechanism for disk ejection in a forcible manner.
2. Description Related to the Prior Art
An optical disk is an information recording medium for use in a computer system or other electronic equipment for storing information of a considerable amount, for example, CD-R/RW, DVD-R/-RW/RAM/+R/+RW. An optical disk drive or player as optical disk device is loaded with the optical disk, and accesses the optical disk to write information to or read information from the optical disk. One of two well-known types of the optical disk drives is a tray type. The tray type includes a disk tray, which is movable between a contained position and an ejection position, and when in the contained position, is contained in a case chassis, and when in the ejection position, protrudes from the case chassis. When the optical disk is set on the disk tray in the election position, the disk tray is entered in the optical disk drive, by manual pressure and then by a motor. The optical disk is set in a chuck position by the disk tray, and is clamped on and driven by the turntable and a chuck head. The pickup head writes or read information to the disk while the disk is driven. When an ejection button is depressed later, the disk tray moves out to the ejection position.
In a slot-in type of optical disk drive, no disk tray is used. It is possible structurally to reduce a thickness and size of the optical disk drive with advantages for use in personal computer or other electronic apparatuses. To load the slot-in type with an optical disk, a user enters a first half of the optical disk through an insertion slot formed in a front bezel of the optical disk drive. In response to the entry through the insertion slot, a loading mechanism is started and advances the disk inclusive of the second half automatically into the optical disk drive.
In any of the tray type and the slot-in type, an ejection button is depressed for ejection of a disk for the purpose of unloading the disk from the optical disk drive. In response to depression of the ejection button, a motor rotates in a backward direction, for carrying out unloading of the disk. Should failure occur according to disconnection of a power source or mechanical failure of the optical disk drive itself, no automatic ejection of the disk can be made. The disk remains in the optical disk drive.
The state of unwanted presence of the disk in the optical disk drive is a serious problem. For the purpose of emergency, an emergency disk ejector is incorporated in the optical disk drive. U.S. Pat. No. 6,654,334 (corresponding to JP-B 3772667) discloses an emergency disk ejector in which a manual driving structure is inserted to push at plural times to rotate a gear intermittently. The gear rotates a loading arm to eject a disk.
In FIG. 16, the emergency disk ejector of U.S. Pat. No. 6,654,334 is illustrated. An ejection slider 100 is a manually operable member. A rack gear 104 is formed on the ejection slider 100. A tension coil spring 101 biases the ejection slider 100 in a direction toward the right in the drawing. A gear unit 103 is not meshed with the rack gear 104. When the ejection slider 100 slides to the left in a range of guide slots 105a and 105b, the rack gear 104 becomes meshed with the gear unit 103.
When the ejection slider 100 is pushed by an emergency pin P as external device, the rack gear 104 causes the gear unit 103 to rotate. The rotation of the gear unit 103 makes it possible to eject a disk forcibly. A worm gear 106 of an output shaft of a motor 102 is meshed with the gear unit 103. Load at the time of the backward rotation of the gear unit 103 is considerably high. Manual operation of the ejection slider 100 requires great force. Mechanical stress in the ejection slider 100 is very high.